Juvenile myositis (JM) causes severe weakness and disfiguring skin rashes. JM symptoms and side effects of treatment can worsen quality of life for youth with JM and their families. Despite the effects that JM can have on quality of life, little is known about mental health in JM. Studies suggest that depression, anxiety, and other mental health issues are common in children with chronic conditions. This study will first assess the feasibility of mental health screening in a JM Center of Excellence. The study will also evaluate the relationship of mental health with indicators of physical health in JM. The study will also assess how mental health affects behaviors that are important for overall health maintenance, such as taking medications, staying physically active, and protecting against sun exposure. Future studies will build on these findings with the goal of improving mental and physical health in youth with JM.